The present invention relates to a composition for treatment for providing stain release or stain repellence properties to substrates, in particular hard surfaces such as natural and man-made stone. In a particular aspect, the composition comprises a fluorinated compound, a potassium or lithium silicate and an acrylic polymer.
Hard surface substrates, in particular natural or man-made stones are frequently used in the building industry and outdoor environment in a decorative way. When left unprotected, hard surfaces may loose their original appearance from exposure to weathering and soil. In order to protect hard surfaces they are often sealed with a film-forming resin, such as an epoxy or urethane product. These coating materials are often quite expensive and may undesirably alter the appearance of the coated substrate.
In order to protect substrates against water and increase the surface strength, moisture resistance coatings have been proposed. For example US2008166486 relates to a moisture resistant concrete coating composition comprising a water dispersible resin, such as an acrylic resin, an alkoxysilane, a mineral aggregate comprising silica and an extender composition comprising a silicate.
U.S. Pat. No. 5,395,658 discloses a method for improving the frost-de-icing salt resistance of concrete structures comprising applying to the surface of a concrete structure an alkali silicate solution.
Fluorochemical-containing treatments have been proposed to render substrates resistant to soil and repellent to water- and oil-based stains. For example, WO2007127267 discloses a composition for treating masonry to improve its stain resistance as well as providing water and oil repellency. The composition utilizes a fluorine-containing polymer and at least one silicone compounds selected from silanes and siloxanes. The composition may be dispersed in an organic solvent for application to the masonry substrate followed by elimination of the solvent.
WO2007127267 discloses a composition for treating masonry to improve its stain resistance as well as providing water and oil repellency. The composition utilizes a fluorine-containing polymer and at least one silicone compounds selected from silanes and siloxanes. The composition may be dispersed in an organic solvent for application to the masonry substrate followed by elimination of the solvent.
U.S. Pat. No. 5,702,509 discloses a composition comprising a polysiloxane reaction product of a) at least one alkoxysilane, alkoxysiloxane or siloxane compound comprising at least one hydrophobic moiety; b) at least one alkoxysilane, alkoxysiloxane or siloxane compound comprising at least one hydrophilic moiety and c) at least one fluorine-containing alkoxysilane compound capable of reaction with component a) and/or b). The composition can be used to render substrates, especially porous substrates water- and oil repellent.